This detail about U.S. Attorney Bobby O'Neill may not seem especially remarkable — unless you have spent time in the rarefied air of federal court, where judges do not deign to mix with the masses, news cameras are unwelcome and good luck prying a comment from the jaws of most prosecutors.

But O'Neill, Irish son of a janitor and a maid, street-smart and savvy, seems to genuinely want people to understand the law. This has included both its limits, like when his office could not prosecute then-state Sen. Jim Norman over a vacation home paid for by a political supporter, as well as its power, like when O'Neill himself put away former County Commissioner Kevin White in a bribery scandal.

"Motivated," a seriously serious O'Neill told a jury in his damning final argument against White, "by greed and avarice."

But here is one of my favorite details about Bobby O'Neill: No matter how much he is teased by people like Tampa Mayor Bob Buckhorn, he wears his dark hair in a workingman's mullet, short on the sides, the back curling down to his collar. But he cuts off that proud mullet-fringe for trials involving high-end, white-collar crimes. There is something to be said for knowing your audience.

If this is starting to sound like a wistful obituary for the top prosecutor of the Middle District of Florida, it sort of is.

O'Neill, 55, had people thinking it was a bad April Fool's joke, this news that he is leaving his "extraordinarily rewarding" job to work for a global risk-management firm called the Freeh Group, as in former FBI director Louis Freeh. This was not greeted with widespread glee, since O'Neill has a reputation for working well with assorted law enforcement agencies and state prosecutors, and not much of one for politics and fiefdoms.

"Good for him and everything," says Hillsborough Sheriff David Gee. "But I hate to hear that."

Pinellas Pasco-State Attorney Bernie McCabe says normally a career prosecutor like O'Neill wasn't the pick for the U.S. attorney job, that it usually went to a guy from a big firm. "Some people just want to have the job," says McCabe, "other people want to do the job." Clearly, he means the current occupant.

Mayor Buckhorn considers O'Neill a good friend; they have shared more than a Guinness or two. But, says Buckhorn, "I couldn't tell you to this day, as close as I am to Bobby O'Neill, whether he is a Democrat or a Republican." No party affiliation, as it turns out — something O'Neill thinks wise when you go after public corruption involving someone in one political party or another.

As the news spread, people kept using the same words about him: approachable, reasonable, pleasant and sharp. And, with apologies to federal prosecutors, maybe the highest compliment of all: He does not act like a federal prosecutor.

And that he is funny. People kept telling me about a story he told at his swearing-in, something about his Catholic school childhood, maybe a priest or a nun. ("I was always a troublemaker," O'Neill reports. "I got hit a lot.") He could not recall the story. "I'm Irish," he explains, meaning there are many stories.

In that rarefied federal court air, ones from prosecutor O'Neill will be missed.